The prior art spacecraft component includes a stator having an elongate axis and having coil means, an inertia wheel with a magnet means, a shaft supported by the stator and supporting the inertia wheel, a floating lower bearing cartridge, a fixed upper bearing cartridge, and a pyrotechnic actuated snubber unit.
One problem with the prior art spacecraft component is that, during launch of the spacecraft and component, the fixed upper bearing cartridge may fail due to axial overload caused by vibration. Load normal to the axis is taken by both bearing cartridges. Axial load is taken only by the fixed upper bearing cartridge. Vibration levels are relatively high during launch and are relatively low after burn-out occurs. The ascent pressure decreases, varying from a ground level ambient pressure of 14.7 pounds per square inch to a hard vacuum of space.
Another problem with the prior art spacecraft component is that the pyrotechnic driven snubbber unit creates a substantial amount of debris and generates a shock load environment that can damage the close tolerance bearings as well as the sensitive components in the areas surrounding the pyrotechnic device.